precarious, unstable -- (affording no ease or reassurance; "a precarious truce")
parlous, perilous, precarious, touch-and-go -- (fraught with danger; "dangerous waters"; "a parlous journey on stormy seas"; "a perilous voyage across the Atlantic in a small boat"; "the precarious life of an undersea diver"; "dangerous surgery followed by a touch-and-go recovery")
precarious, shaky -- (not secure; beset with difficulties; "a shaky marriage")
(Sound)
